Fluoro cyclohexenyl or cyclopentenyl alkyl sulfides



United States Patent 3,363,000 FLUORO CYCLOHEXENYL 0R CYCLGPENTENYL ALKYL SULFIDES Melvin M. Schlechter, New Hyde Park, N.Y., and Richard F. Sweeney, Dover, N.J., assiguors to Allied tlhemical Corporation, New York, N.Y., a corporation of New York No Drawing. Filed Apr. 5, 1965, Ser. No. 445,727 Claims. (Cl. 260-639) ABSTRACT OF THE DISCLOSURE Unsaturated, alicyclic, halogen-containing thioethers having the formula wherein X is fluorine or chlorine, wherein n is 0 or 1, and wherein R is an alkyl radical, there being at least one fluorine atom present in the molecule, are prepared by base-catalyzed reaction of perhaloalkenes having the formula C 7 X2 wherein X and n have the aforestated meanings, with an alkyl mercaptan (RSH) in the presence of an inert polar organic solvent. The thioethers are useful as solvents and sealants for polymers, terpolymers, and copolymers of chlorotrifluoroethylene.

This invention relates to the production of a novel class of unsaturated, alicyclic, halogen-containing thioethers.

An object of this invention is to provide a novel class of chemical compounds and more particularly to provide a class of halogentated cyclopentenyl and cyclohexenylthioethers, hereinafter referred to as thioethers, which thioethers are characterized by the presence of a chlorine atom on one of the unsaturated carbon atoms of the cycloalkenyl group, all of the saturated cyclic carbon atoms being perhalogenated with either fluorine or chlorine atoms, there being present at least one fluorine atom in the molecule.

Another object of the invention is to provide a process for the production of the above-described thioethers.

Other objects and advantages of the invention will become apparent from a consideration of the following description and discussion of the subject invention.

The novel thioethers of the invention may be represented by the following formula:

n Zn wherein X may be F or C], It may be 0 or 1 and R is an alkyl radical, preferably containing from 1-8 carbon atoms, there being at least one fluorine atom present in the molecule.

It has been found that the above-described thioether compounds have utility as solvents for polymers, terpolymers and copolymers of triiluorochloroethylene an as sealing adjuvants for films of such polymers.

The novel thioethers may be prepared by reacting a 1,2-dichloroperhalocycloalkene-1 of the formula:

wherein X may be F or Cl and It may be 0 or 1, there being at least one fluorine atom present in the molecule, with a mercaptan of the formula:

R-SH

wherein R is an alkyl radical, straight or branched chain, preferably containing from 1-8 carbon atoms, and an inorganic base, in the presence of an inert polar solvent, preferably an alkanol.

Inorganic bases utilizable must be soluble in the solvent to be employed and are exemplified by the following: alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides and alkaline earth metal carbonates.

Inert polar solvents are well known in the art, ethyl alcohol, dioxane, diglyme and dimethylformamide being illustrative.

The preferred alkanol solvent may be straight or branched chain and may contain any feasible number of carbon atoms. Illustrative members of this group include methanol, ethanol isopropanol, n-butanol and neopetanol.

The reaction may be illustrated by the following equation:

wherein R is as definedabove.

Where the corresponding halogenated cyclopentenyl thioethers are desired, the corresponding 1,2-dichloroperhalocyclopentene-l is employed and the reaction proceeds O substantially in the same way.

There is no criticality in the number of carbon atoms which may be contained in the alkyl radical of the RSH reactant. The only limitations are the practical ones of stability and solubility of the resulting mercaptan molecule in the reaction medium-to be employed.

Alkyl mercaptans (RSH) may be prepared, as is known in the art, by the reaction of alkyl halides with sodium or potassium hydrosulfide. By this method, alkyl mercaptans containing twelve (n-C H SH) or more carbon atoms have readily been prepared.

The 1,2-dichloroperhalocycloalkene-l starting materials may be prepared by known procedures which are reported in the literature. For example, perchlorocyclopentene may be fluorinated with SbF to a mixture of 1,2-dichloroperhalocyclopentene(s)-l, in which the halogen atoms consist of varying proportions of fluorine to chlorine and which fluorine atoms may be in a variety of positions. This procedure is reported by Henne et al., J.A.C.S., vol. 67, No. 8 (Aug. 9, 1945) pp. 1235-36. The corresponding 1,2-dichloroperhalocyclohexene(s)-1 may be prepared by an analogous procedure and also by fluorinating hexachlorobenzene with SbF at temperatures below about (3., as reported by Leiller, J. Org. Chem., vol. 24 (1959), pp. 1132-33, or by fiuorinating hexachlorobenzene with a 50% excess of ClF3, as reported by Chambers et al., Tetrahedron, vol. 19 (1963) pp. 891-892 (Pergamon Press Ltd, Northern Ireland).

The reaction of the invention may be carried out in conventional vessels constructed of ordinary materials, such as Pyrex or steel, which vessels are preferably equipped with stirring means, condensing means and tion was complete, at which time the solution was allowed to cool to room temperature. To the mixture at room temperature were added 24.8 g. (0.399 mole) of ethyl mercaptan. Upon addition of this material, the solution turned 1,2,3,3,4,4,5,5-oetachlorodifiuorocyclohexened n-Hexyl-mercaptan n-O ctyl-mercaptan Isopropy1-mereaptan Neopentyl-meroaptan.

means for adding the mercaptan reactant slowly, such as 5 orange in color and the resulting orange solution was added a dropping funnel. slowly, with stirring, to a chilled solution of 108 g. (0.366 The process aifords the advantages of operation at mole) of 1,2-di-chlorooctafluorocyclohexene-1 in 100 ml. atmospheric pressures and at low temperatures. Superof ethanol. Temperature of the reaction mixture was mainatmospheric or subatmospheric pressures may be emtained between about 010 C. throughout the addition, by ployed, however, with no particular benefit. 1O quenching the reaction vessel in ice-water. After comple- The reaction may be carried out over a relatively wide tion of the addition the orange organic layer separated range of temperatures, the upper limit being the boiling and was washed with small portions of water. The orange point of the solvent employed. Temperatures below about organic portion was then taken up in methylene chloride 30 C. are generally preferred for good results. Better reand dried over sodium sulfate. Following solvent removal, sults are obtained when the reaction is carried out at the residual oil was distilled and 35.9 g., corresponding temperatures between about 020 C. and optimum reto a yield of about 27%, of a yellow oil, identified as sults are obtained when temperatures are maintained be- 1-ethylthio-2-chlorooctafluorocyclohexene-1 (B.P. 74-76 tween about 010 C. Temperatures below about 0 C. C./ 10 mm.),were recovered. are operable, however, decreased yields are obtained due Analysis.--Calculated for C H CIF S C, 30.0%; H, to the increase in viscosity of the reactant solutions. 1.56%; F, 47.4%; S, 9.98%; Cl, 11.1%. Found: C, 29.6%;

The reaction is mildly exothermic and accordingly it is H, 1.52%; F, 46.0%; S, 9.34% Cl, 11.1%. necessary to positively control the reaction temperatures Infrared spectographic analysis showed the following abto within the desired limits. This may be accomplished by sorptions in microns (w=weak, s=strong): 3.32, 3.39 regulation of mixing of the reactants to control exotherm, (w.), 3.48 (w.), 6.30 .(s.), 6.89 (w.), 7.21 (w.), 7.45 (s.), by removal of heat of reaction, by any conventional cool- 7.90 (w.), 8.15 (s.), 8.28 (s.), 8.55 (s.), 8.90 (s.), 9.56 ing means, orby any combination ofthe above. (s.), 10.09 (s.), 11.31 (s.), 11.95 (s.). The strong ab- For maximum yields, the perhalocycloalkene, alkyl sor-ption peak at 6.30 microns confirmed the presence of mercaptan and inorganic base reactants are employed in an unsaturated double bond. Strong absorption signals in their stoichiometric amounts, i.e. equimolar portions. As the area of the CF stretch region (8.15-8.55 microns) little as 0.1 mole of inorganic base per mole of perhaloconfirmed the presence of C-F bonds. Weak absorption cycloalkene may be used and the reaction will proceed, signals in the area of the CH stretch region (3.32-3.48 except that diminished yields of the corresponding thiomicrons) confirmed the presence of C-H bonds. The inether product will be obtained. Similarly, if the concenfrared analysis was thus consistent with the expected tration of the alkyl mercaptan reactant, with respect to the structure. perhalocycloalkene, is reduced, the reaction will proceed Example 2 but proportionately less of the desired thioether product A threemecked flask, fiquipped with a watepcookd 31 3233233 2; 2222: 32 sg i g z giz igg i gggg condenser, dropping funnel and stirrer is charged with the reactiog 1 S y 150 ml. of absolute ethanol and 16.0 g. (0.400 mole) of The amount of solvent re uired is that amount needed sOdm-m l-lydmxlde' The reiulm-lg mlxture he-ated until t k th t t 1 G u 1 5O rt b solution is complete, at WhlCh t1me the solution s allowed 0 eep 6 mac an s m so enera y pa 5 y to cool to room temperature. To the mixture at room voluma. of Solvent. Per combmed parts of the other reac' temperature is added 24.8 g. (0.399 mole) of ethyl merthls purpose Preferably .about 5-10 ig captan. Upon addition of this material, the solution turns y v0 ume of alkanol solvent per combined parts of 6 orange incolor and the resulting orange solution is added other reactants are employed h h slowly, with stirring to a chilled solution of 98 g. (0.40 gf ig gg for preparmg t e thlfet g mole) of 1,2-dichlorohexafluorocyclopentene-1 in 125 ml. prises mg e y mercaptfm reactant 0 u Ion of absolute ethanol. Temperature of the reaction mixture of t morg.amc.base reactant m the Solvent W.h1ch is maintained between about 0-10 C. throughout the addii t sohmon 15 then slowly added to a Solutlon 5 tion, by quenching the reaction vessel in ice-water. After taming the oleiin reactant m the solvent. The ole 0 completion of the addition, the orange organic layer sepmercaptan and morgamc base reactants may be mixed arates and is washed with small portions of water. The Simultaneously howgver or thimercaptari added. to the orange organic portion is then taken up in methylene chloolefin reactant followed by addltlon of t ride and dried over sodium sulfate. Following solvent The Products may be rec.overed as conventional removal, the residual oil is distilled and about 26.5 g. of z' fig yi gg gi g extras/0n and drying followed by a yellow oil, identified as 1-ethylthio-2-chlorooctafluoro- The products and process of the invention are further cyclop mum-1 1s recovered illustrated by the following examples in which parts and Examples Percentages are byrwelghtr unless otherw 1S6 mdlcated- The process of Example 2 is repeated with the reactants listed in the indicated columns of Table I. The correspond- Example 1 ing products obtained are listed oppositely in the last col- A three-necked flask, equipped with a water-cooled umn. In Examples 3-6, KOH is used as the inorganic condenser, dropping funnel and stirrer was charged with base and isopropanol is used as the solvent. In Examples 150 ml. of ethanol and 16.0 g. (0.400 mole) of sodium 79, Na CO is used as the inorganic base and dimethylhydroxide. The resulting mixture was heated until soluformamide is used as the solvent.

TABLE I Example Halogenated Cycloalkene Reaetant V Mercaptan Reactant Thio Product 3 1,2-dichlorooctatluorocyclohexened Methyl-mercaptan 1-rnethylthio-2-ehlorooctafluorocyclohexene-l. 4 (in Propyl-mercaptan l-propylthio-2-chlorooctafluorocyclohexenal.

1,2-dichlorohexafluorocyclopentene-l. ltlethyhmeroaptanunu l-rnethylthio-Z-chlorohexafiuorocyolopenteue-l.

1-n hexylthio-2-ohlorohexafiuorocyolopentene-l. l-n-octylthi0-2,3,3,4,4,5,5-heptachlorodifluoroeyclohexene-l. Lisopropylthio-Z,3,3-trichl0rotetrafluorocyclopentene-l. 1-neopentylthi0-2,3,4-trichlorohexafluorocyclohexenel.

When the inorganic bases and solvents employed in Examples l-9 are interchanged or substituted by other inorganic bases and solvents as defined hereinbefore, substantially the same results are obtained.

Example 1-thioethyl-2-chlorooctafluorocyclohexene-1 was tested as a sealing adjuvant for strips of thermoplastic film composed of a copolymer of about 96% trifluorochloroethylene and about 4% vinylidene fluoride. A saturated solution of this polymer in the thioether was prepared by refluxing the thioether with said polymer, cooling the mixture to room temperature and decanting the solution from the undissolved polymer. A pair of polymer film strips was sealed together without the use of sealing adjuvant. Another pair of polymer film strips was sealed together, this time employing as sealing adjuvant the abovedescribed polymer solution in the thioether. The thioether sealing adjuvant solution was applied by merely coating, as by brushing, the inner surfaces of the film strips to be sealed. An impulse heat sealer was used. The impulse heat sealer was a Sentinel Impulse Sealer. Sealing pressure was 30 psi. The heat sealing temperature Was 375 F. The dwell time for the seal, or in other words, the length of time during which the pressure and heat were applied to efiect the seal, was three (3) seconds. It was attempted to test the seal strength by measuring the amount of force needed to rupture or pull apart the seal. The sealing adjuvant, however, apparently had an afiect on the strength of the polymer film in the vicinity of the seal, for the polymer film ruptured before the seal, at a point away from the sealing area. As can be seen from the following table, the polymer film strip pair sealed with the adjuvent solution, ruptured at a weight considerably higher than the polymer film stn'p pair which was sealed without such a treatment.

TABLE II Wgt. to eflect rupture (gram) Film strips heat-sealed without the use of adjuvant 10 Film strips heat-sealed witha polymer solution in l-thioethyl-Z-chlorooctafluorocyclohexene-l 2,994

Although a copolymer of about 96% trifluorochloroethylene and about 4% vinylidene fluoride was employed, a wide variety of polymers, terpolymers and copolymers of trifluorochloroethylene may be emlpoyed with equivalent results; homopolymeric trifluorochloroethylene and copolymers of trifluorochloroethylene with vinyl chloride, 1,1-chlorofluoroethylene, tri-fluoroethylene and perfiuorobutadiene being exemplary. In general class of composithose compositions containing upwards of by weight of trifiuorochloroethylene. The general class of compositions described above can be referred to generically as polytrifluorochloroethylene.

When other thioether products within the scope of the invention, such as those listed in the last column of Table I, are used as sealing adjuvants for films of polytrifluorochloroethylene, substantially the same results are obtained; that is to say, films of polytrifluorochloroethylene which are heat sealed employing such adjuvants, rupture at weights considerably higher than films of polytrifluol'ochloroethylene which are heat sealed without using sealing adjuvants.

Since various changes and modifications may be made without departing from the spirit of the invention, the invention is to be limited only by the scope of the appended claims.

We claim: 1. Compounds of the formula:

CnXZn X20 0-01 X20 )SR where X is F or Cl, 11 is 0 or 1 and R is an alkyl radical, there being at least one fluorine atom present in the molecule.

2. Compounds according to claim 1 in which n is 0. 3. Compounds according to claim 1 in which n is 1. 4. Compounds according to claim 1 in which R is an alkyl radical containing 1-8 carbon atoms.

5. Compounds according to claim 4 in which n is 0. 6. Compounds according to claim 4 in which n is 1. 7. 1-ethylthio-2-chlorohexafluorocyclopentene-1. 8. l-proplythio-Z-chlorohexafluorocyclopentene-1 9. 1-ethylthio-2-chlorooctafiuorocyclohexene-1 10. 1-propylthio-2-chlorooctafluorocyclohexene-l References Cited Reid, Organic Chemistry of Bivalent Sulfur, vol. II, pp. 24-25 (1960) QD 412 SIR4 C.2.

JOSEPH P. BRUST, Primary Examiner.

D. R. PHILLIPS, Assistant Examiner. 

